The aim of this proposal is to thoroughly investigate Timolol, a beta-adrenergic blocking agent, regarding its use as a new topical medication for glaucoma. Preliminary studies have proven its efficacy for lowering intraocular pressure in glaucoma patients. These preliminary studies have shown no side effects of this medication. Preliminary studies strongly suggest that this drug may be a new, effective, innocuous, once-a-day topical drug for the treatment of glaucoma. Before this drug can be recommended for use in the general population its efficacy must be more firmly established and its safety proven (aims of this proposal). Multiple clinical studies in glaucoma patients, using established techniques, are planned. Basic pharmacologic evaluations (dose-response; duration of action, mechanism of action, etc.) will be done. These will be followed by controlled evaluations (drug interactions, biological variations, etc.) and then extended clinical evaluation to ascertain efficacy and safety. Animal studies are also proposed. Preliminary studies with this drug are very promising and if it performs well through extending studies (this proposal) then it will become the first drug to be added to our glaucoma armementarium in over 20 years.